• Journal of Microbiology and Biotechnology
• /
• v.12 no.5
• /
• pp.841-843
• /
• 2002

Pfu DNA polymerase from Pyrococcus furiosus was expressed in the E. coli periplasm, and the fully active polymerase was partially purified by applying osmotic shock, ammonium sulfate precipitation, and heat treatment. This method represents a new way of expressing and purifying functional Pfu DNA polymerase without the use of chromatography.

• Korean Chemical Engineering Research
• /
• v.47 no.5
• /
• pp.624-629
• /
• 2009

It is the most important step to screen soluble and insoluble proteins when we attempt to improve the solubility of recombinant proteins through directed evolution approach. Here we show that the solubility of a recombinant protein in vivo can be examined by expressing the recombinant protein with beta-lactamase as a fusion partner. First we constructed an expression system which can produc a fusion protein with the C-terminal of beta-lactamase. Two soluble proteins, i.e. adenine deaminase and aspartate aminotransferase, and insoluble GlcNAc-2-epimerase were cloned into the developed expression vector, respectively. We investigated the effect of the expression of the three recombinant fusion proteins on the growth of E. coli, and confirmed that the solubilities of the recombinant proteins correlated with cell growth rates.

• Journal of Microbiology
• /
• v.45 no.2
• /
• pp.179-184
• /
• 2007

Pasteurella multocida, a Gram-negative facultative anaerobic bacterium, is a causative animal pathogen in porcine atrophic rhinitis and avian fowl cholera. For the development of recombinant subunit vaccine against P. multocida, we cloned and analyzed the gene for outer membrane protein H (ompH) from a native strain of Pasteurella multocida in Korea. The OmpH had significant similarity in both primary and secondary structure with those of other serotypes. The full-length, and three short fragments of ompH were expressed in E. coli and the recombinant OmpH proteins were purified, respectively. The recombinant OmpH proteins were antigenic and detectable with antisera produced by either immunization of commercial vaccine for respiratory disease or formalin-killed cell. Antibodies raised against the full-length OmpH provided strong protection against P. multocida, however, three short fragments of recombinant OmpHs, respectively, showed slightly lower protection in mice challenge. The recombinant OmpH might be a useful vaccine candidate antigen for P. multocida.

• BMB Reports
• /
• v.28 no.3
• /
• pp.238-242
• /
• 1995

The tadpole H-ferritin produced in E. coli was purified and its molecular properties were investigated to obtain information about the contribution of the H-subunit in the reaction of iron core formation. All the expressed subunits were assembled into complete holoprotein in vitro, presumably 24-mer, and the protein was heat-stable. Electron microscopy revealed that the recombinant ferritin forms spherically and contains iron core. No difference was observed in the absorption spectrum of the expressed protein compared to that of the natural ferritin. The Ouchterlony double diffusion of the expressed protein showed that the H-chain ferritin shares an antigenic determinant with natural tadpole ferritin. Rabbit anti-horse spleen ferritin discriminated the H-ferritin from natural ferritin. The rate of ferritin formation by the recombinant H-chain apoferritin was determined to be higher than that shown by natural tadpole ferritin, which consists of H, M and L-subunits. This phenomenon may be caused by the absence of M and L-subunits in the recombinant H-chain apoferritin.

• Microbiology and Biotechnology Letters
• /
• v.34 no.3
• /
• pp.273-277
• /
• 2006

To investigate the antigenicity and protective immunity of outer membrane protein H (OmpH) in Pasteurella multocida D:4, the recombinant OmpH protein was produced in Escherichia coli. The truncated and Trx-fused form of recombinant OmpH (53 kDa) was purified, and used as an antigen in the immunization and challenge experiment. The immunized mice with the recombinant OmpH produced a high-titer antibody, and had protective immunity against P. multocida as same level as the mice immunized with formalin-killed whole cell.

• Korean Journal of Veterinary Research
• /
• v.46 no.1
• /
• pp.13-19
• /
• 2006

Generally known psittacosis or ornithosis is a disease of birds caused by the bacterium Chlamydia psittaci. Humans are accidential hosts and are most commonly infected from avian sources. It raises hepatitis or neurosis. As major outer membrane protein (MOMP) of Chlamydia psittaci has been known to play a role in the avoidance of host immune defenses, research on developing a Chlamydia vaccine has focused on the MOMP. In this study, the gene encoding the major outer membrane protein (MOMP) of the Chlamydia psittaci strain 6BC was cloned and expressed in Escherichia coli strain M-15. The recombinant DNA was cloned by fusion prokaryotic expression vector pQE30-GFPII. Expression of the recombinant protein was performed in E. coli and was induced by IPTG. The size of expressed recombinant protein is 74.220 kDa (MOMP, 43.260 kDa; GFP expression region, 30 kDa; $6{\times}His$ tag, 960Da). This protein was purified by using his-tagging-inclusion body. Recombinant protein was reconfirmed through ELISA test and western blot with antibody against pQE30-GFPII. It will be useful antibody development.

• Animal cells and systems
• /
• v.16 no.6
• /
• pp.455-461
• /
• 2012

Amongst the various antimicrobial peptides, lysozyme plays a central role in initiating and maintaining the antibacterial defense response of insect. Here we propose the biosynthesis and refolding of recombinant lysozyme in Escherichia coli expressed in inclusion body form. The Agrius lysozyme gene was amplified using gene specific primers and then ligated into the pGEX-4T-1 vector, which contained the glutathione S-transferase (GST) gene as a fusion partner. A recombinant lysozyme was expressed in E. coli Rosetta cells using a pGEX-4T-1 expression vector, and the fusion protein was induced by ioporpyl-${\beta}$-D-thiogalactopyranoside (IPTG). The recombinant protein produced as an inclusion body was resolubilized in solubilization buffer, and the resultant solution was dialyzed in refolding buffer. After thrombin cleavage, the recombinant lysozyme was purified by ion exchange chromatography and reverse phase chromatography. The recombinant lysozyme was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis and immunoreactivity against the anti-Agrius lysozyme was observed by western blot analysis of this protein. The recombinant lysozyme displayed antibacterial activity against Bacillus megaterium and Micrococcus luteus, which was confirmed by the inhibition zone assay.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.24 no.1
• /
• pp.23-27
• /
• 2012

Porcine circovirus type 2 (PCV2) is a single-stranded circular DNA virus associated with Postweaning multisystemic wasting syndrome (PMWS), which is considered to be an important infectious swine viral disease. PCV2 capsid protein encoded by ORF2 is a structural protein and expected as the high immunogenicity protein. In this study, we generated recombinant baculovirus containing ORF2 of PCV2 and analyzed the optimal conditions for the production of capsid protein in insect cell. Production and status of recombinant capsid protein in insect cell were confirmed by SDS-PAGE and Western blot analysis using His tag antibody and anti-PCV2 serum. The yield of recombinant capsid protein was high like as shown visible on SDS-PAGE. Optimal multiplicity of infection (MOI) and infection time of recombinant virus were determined as 5 MOI and 4 days, respectively. ORF2 is known to have N-linked glycosylation site, but we couldn't detect the glycosylation of recombinant protein in insect cells.

• Journal of Plant Biotechnology
• /
• v.4 no.3
• /
• pp.95-101
• /
• 2002

Molecular faming has the potential to provide large amounts of recombinant protein for use in diagnostics and as therapeutics. Various strategies have been developed to enhance the expression level, stability, and native folding of recombinant proteins produced in plants. Few investigations into the subcellular distribution of recombinant proteins within plant cells have been published despite the potential to increase the expression level and impact the purification process. This review article discusses the current strategies used for targeting recombinant proteins to various subcellular locations and the advantages of targeting to seed oil bodies for molecular farming applications. Specifically, the affinity capture of antibodies using recombinant oilbodies is discussed.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.8
• /
• pp.1116-1122
• /
• 2013

Cell line development is the most critical and also the most time-consuming step in the production of recombinant therapeutic proteins. In this regard, a variety of vector and cell engineering strategies have been developed for generating high-producing mammalian cells; however, the cell line engineering approach seems to show various results on different recombinant protein producer cells. In order to improve the secretory capacity of a recombinant tissue plasminogen activator (t-PA)-producing Chinese hamster ovary (CHO) cell line, we developed cell line engineering approaches based on the ceramide transfer protein (CERT) and X-box binding protein 1 (XBP1) genes. For this purpose, CERT S132A, a mutant form of CERT that is resistant to phosphorylation, and XBP1s were overexpressed in a recombinant t-PA-producing CHO cell line. Overexpression of CERT S132A increased the specific productivity of t-PA-producing CHO cells up to 35%. In contrast, the heterologous expression of XBP1s did not affect the t-PA expression rate. Our results suggest that CERT-S132A-based secretion engineering could be an effective strategy for enhancing recombinant t-PA production in CHO cells.